Angularjs what is the differences of handling ajax from success/error and promise? -

i'm not sure should handle response of ajax request.

there 2 flavours.

1. handle via success/error callback $http.
2. handle via then() method promise result.

both responds expected. but, suppose there 'catch' use each one. google didn't show me way. , angular.js source code kinda... cryptic me.

notice: example (1) responds first , (2) responds next. think because localhost latency null , both async method.

$http({     method: 'post',     url: 'ping.php',     headers: {'content-type' : 'application/json'} }). success(function(data, status, headers, config) {     console.log("flavour 1 success"); }). error(function(data, status, headers, config) {     console.log("flavour 1 error");                        }).then(function() {      console.log("flavour 2 success"); },          function() { console.log("flavour 2 error");  

});

according angular documentation,

{httppromise} – returns promise object standard then method , 2 http specific methods: success , error. then method takes 2 arguments: success , error callback called response object. success , error methods take single argument - function called when request succeeds or fails respectively.

to answer question, difference success , error take 1 argument, whereas then takes 2 arguments.

the first invoked before second, because you've listed in order, , that's how promises work. if had listed then, invoked third.